I rolled a Monk, just to try it, it's said to be the easier of the two melee focused classes. My god. I've smacked all main bosses without dying a single time, Act 1 main boss in his last phase was ended in one go; he didn't even get to summon his friends. The damage output is insane, at least for now. I have over twice the DPS my Mercenary or Warrior had at the end of Act 2, except I'm still at the very beginning of Act 2 (stacks yield about 950DPS at level 21, and this is without the Tempest Bell wreaking havoc).
For early game (Act 1 and 2 at least), I can't see how anything beats this for bosses, it literally takes less than 6 seconds to mangle many of them (that's the duration of the Bell).